I have noticed a slight increase in advisories from ATC and it usually seems to be below our cruise altitudes. I think NEXRAD will "overstate" the precip because it's an extremely sensitive instrument. So it may pick up dense clouds where other radar's won't.

FWIW, NEXRAD's advantage over conventional wx radar is it detects the movement of the precipitation within the individual cells. So, although any radar will show time-lapse movement of a wx system, NEXRAD will show water droplet movement. This helps in detecting rotation prior to any tornadoes forming.